Apple got a head start on Google with the App Store, but over the last year, Google Play has continued to make up ground, not only with its offerings of apps, but also the amount of revenue it generates.
In Q4 2012, Apple’s App Store was still seeing four times as many sales as Google Play was, but fast forward to Q1 2013 and the App Store is now only making 2.6 times as much as Google Play.